bugGNU Octave - Bugs: bug #38134, [octave forge] (signal) bug in...


bug #38134: [octave forge] (signal) bug in remez

Submitted by:  CarnĂ« Draug <carandraug>
Submitted on:  Mon 21 Jan 2013 03:22:30 PM UTC  
Category:  Octave Forge Package Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Confirmed Assigned to:  None
Originator Name:  Open/Closed:  Open
Release:  dev Operating System:  Any

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Fri 21 Jun 2013 03:37:59 AM UTC, comment #1: 

Confirmed that the remez() function does give poor results for the given example, although I don't see exactly the same coefficients as reported.

Mike Miller <mtmiller>
Project Administrator
Mon 21 Jan 2013 03:22:30 PM UTC, original submission:  

The following was reported on the mailing list on 15/01/2012 by Anders Brandt. nabble thread.

I am experiencing problems with the remez command in Octave 3.2.4 on Windows. I have tried a number of different orders and griddensities, but all seem to give error. I am trying to define a differentiator.


B=remez(4,[0 0.8],[0 0.8]*pi,'differentiator',4*1024) gives me coefficients
  -0.02488   0.35098  -1.00103   0.00000 ... (neg. symmetry)

MATLAB's firpm, which I understand should give the same (similar) output, gives

B=  0.1519   -0.4161    0.9424         0

The MATLAB result is a really decent differentiator, which cannot be said about the remez output.

Robert T. Short commented:

I don't think this function works.  I have not tried it in a long time, but I never got any useful results. I played around with it enough to believe it would not be hard to fix, but it has never bubbled up the priority stack enough to actually do it.


Carnë Draug <carandraug>
Project Member


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Attach Files:

Attached Files
file #32732:  Bug38134.patch added by laurentg (14KiB - application/octet-stream - See Bug38134.patch for a fix attempt (including tests against other sources I could find))


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -email is unavailable- added by jwe (Updated the item)
  • -email is unavailable- added by laurentg (Updated the item)
  • -email is unavailable- added by carandraug (original bug reporter)

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    Follow 7 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2019-02-27 mtmiller Carbon-CopyRemoved 80942 => -
    2017-08-13 jwe Summarysignal package: bug in remez => [octave forge] (signal) bug in remez
    2014-12-30 carandraug Carbon-CopyRemoved 79703 => -
    2014-12-30 laurentg Attached File- => Added Bug38134.patch, #32732
    2013-06-21 mtmiller StatusNone => Confirmed
        Operating SystemMicrosoft Windows => Any
    2013-01-21 carandraug Carbon-Copy- => Added anders.brandt@abravibe.com

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